Organic light emitting elements are vulnerable to moisture and/or oxygen. Organic light emitting elements may suffer from delamination at an interface between a metal field and a light emitting layer due to moisture. In addition, the organic light emitting elements may have high resistance due to oxidation of metals and may suffer from degradation of organic materials in the light emitting layer due to moisture and/or oxygen. The organic light emitting element may suffer from deterioration in light emission property due to oxidation of the light emitting layer or the metal field by outgassing inside or outside the organic light emitting elements. Thus, the organic light emitting element must be encapsulated by an encapsulation composition capable of protecting the organic light emitting element from moisture and/or gas.
The organic light emitting element may be encapsulated by an encapsulation layer having a multilayer structure in which an organic layer and an inorganic layer are alternately stacked one above another. The inorganic layer may be formed by plasma deposition. However, the organic layer may be etched by plasma. Etching may deteriorate an encapsulation function of the organic layer and provide adverse influence on formation of the inorganic layer. The organic layer is formed between two adjacent inorganic layers. When the organic layer has high surface roughness, it will be hard to form an inorganic layer. As a result, the organic light emitting element may suffer from deterioration in light emitting property and reliability.
The encapsulation layer includes a plurality of inorganic layers on a substrate. Thus, the encapsulation layer may suffer from delamination between the inorganic layers and/or delamination or slight lifting between the substrate and the inorganic layer. As a result, the inorganic layers may not sufficiently prevent permeation of moisture and/or oxygen into the organic light emitting element.
The encapsulation layer includes a plurality of inorganic layers on a substrate. Thus, the encapsulation layer may suffer from delamination between the inorganic layers and/or delamination or slight lifting between the substrate and the inorganic layer. As a result, the inorganic layers may not sufficiently prevent permeation of moisture and/or oxygen into the organic light emitting element.
The background technique of the invention is disclosed in Korean Patent Laid-Open Publication No. 2011-0071039.